Liquid crystal display and manufacturing method thereof

ABSTRACT

A liquid crystal display is provided. The liquid crystal display includes a substrate, a thin film transistor disposed on the substrate, a pixel electrode connected with a terminal of the thin film transistor, a microcavity disposed on the pixel electrode, the microcavity including a liquid crystal injection hole disposed at an edge of the microcavity, a supporting member disposed on the microcavity, a first hydrophobic layer disposed on an edge portion of the supporting member, and a capping layer disposed on the supporting member with the capping layer covering the liquid crystal injection hole.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2012-0132573 filed in the Korean IntellectualProperty Office on Nov. 21, 2012, the entire contents of which areincorporated herein by reference.

BACKGROUND

(a) Technical Field

The present invention relates to a liquid crystal display and amanufacturing method thereof.

(b) Description of the Related Art

A liquid crystal display is commonly used in flat panel displays. Theliquid crystal display may include two sheets of panels having fieldgenerating electrodes (e.g., pixel electrodes, common electrodes, orother types of electrodes) and a liquid crystal layer interposedtherebetween.

When a voltage is applied to the field generating electrodes, anelectric field is generated in the liquid crystal layer. The electricfield determines the direction of liquid crystal molecules in the liquidcrystal layer and controls polarization of incident light, so as toprovide images on the liquid crystal display.

A nano crystal display (NCD) is a type of liquid crystal display. An NCDmay be manufactured by forming a sacrificial layer (e.g., an organicmaterial) on a substrate, forming a supporting member on the sacrificiallayer, removing the sacrificial layer to form a cavity beneath thesupporting member, and injecting liquid crystal material into thecavity.

Before injecting the liquid crystal material into the cavity, analigning agent may be applied to the cavity in order to facilitate thearrangement and alignment of liquid crystal molecules in the cavity.After the aligning agent is applied to the cavity, drying may berequired to drive out the solvent components in the aligning agent.However, in the process of drying the aligning agent, solids in thealigning agent may coalesce to form large clusters of solids in thecavity (or at the opening of the cavity). The large clusters of solidscan obstruct the flow of the liquid crystal material into the cavity,and impact the arrangement and alignment of liquid crystal molecules inthe cavity. As a result, the liquid crystal display may have defectsarising from light leakage or transmittance deterioration.

SUMMARY

The present disclosure is directed to address at least the aboveproblems relating to the flow of a liquid crystal material in a liquidcrystal display.

According to an embodiment of the inventive concept, a liquid crystaldisplay is provided. The liquid crystal display includes a substrate, athin film transistor disposed on the substrate, a pixel electrodeconnected with a terminal of the thin film transistor, a microcavitydisposed on the pixel electrode, the microcavity including a liquidcrystal injection hole disposed at an edge of the microcavity, asupporting member disposed on the microcavity, a first hydrophobic layerdisposed on an edge portion of the supporting member, and a cappinglayer disposed on the supporting member with the capping layer coveringthe liquid crystal injection hole.

In some embodiments, the liquid crystal display may include a secondhydrophobic layer disposed between adjacent microcavities.

In some embodiments, the microcavity may include a plurality of regions,and the liquid crystal display may include a groove formed betweenadjacent regions, with the capping layer covering the groove.

In some embodiments, the second hydrophobic layer and the capping layermay be disposed in contact with each other in the groove.

In some embodiments, the first hydrophobic layer may include a firstportion disposed at a top surface of the supporting member and a secondportion extending from the first portion, with the second portiondisposed on a surface of the supporting member along a lateral surfaceof the groove.

In some embodiments, the liquid crystal display may include an organiclayer disposed on portions of the substrate, and a light blocking memberdisposed between adjacent organic layers, wherein the second hydrophobiclayer is disposed on a portion of the light blocking member.

In some embodiments, the liquid crystal display may include a commonelectrode disposed on the microcavity.

In some embodiments, a surface of the pixel electrode surrounding themicrocavity and a surface of the common electrode may have a hydrophilicproperty as a result of being subjected to hydrophilic processing.

In some embodiments, the liquid crystal display may include an alignmentlayer disposed between the pixel electrode and the microcavity, orbetween the common electrode and the microcavity.

In some embodiments, the microcavity may include a liquid crystalmaterial.

In some embodiments, the first hydrophobic layer may include carbon,hydrogen, or fluorine.

According to another embodiment of the inventive concept, a method ofmanufacturing a liquid crystal display is provided. The method includesforming a thin film transistor on a substrate, forming a pixel electrodeon the thin film transistor is formed, forming a sacrificial layer onthe pixel electrode, forming a supporting member on the sacrificiallayer, forming a microcavity by removing the sacrificial layer, whereinthe microcavity includes a liquid crystal injection hole formed at anedge of the microcavity, forming a first hydrophobic layer on an edgeportion of the supporting member, injecting a liquid crystal materialinto the microcavity, and forming a capping layer on the supportingmember so as to cover the liquid crystal injection hole.

In some embodiments, the method may include forming a second hydrophobiclayer between adjacent microcavities.

In some embodiments, the microcavity may include a plurality of regions,and the method may include forming a groove between adjacent regions,with the capping layer covering the groove.

In some embodiments, the method may include forming the secondhydrophobic layer and the capping layer in contact with each other inthe groove.

In some embodiments, forming the first hydrophobic layer may includeforming a first portion disposed at a top surface of the supportingmember and forming a second portion extending from the first portion,with the second portion disposed on a surface of the supporting memberalong a lateral surface of the groove.

In some embodiments, the method may include forming an organic layer onportions of the substrate, and forming a light blocking member betweenadjacent organic layers, wherein the second hydrophobic layer is formedon a portion of the light blocking member.

In some embodiments, the method may include forming a common electrodeon the sacrificial layer.

In some embodiments, the method may include performing hydrophilicprocessing on a surface of the pixel electrode surrounding themicrocavity and on a surface of the common electrode.

In some embodiments, the method may include forming an alignment layerbetween the pixel electrode and the microcavity, or between the commonelectrode and the microcavity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating a liquid crystal display according toan exemplary embodiment of the inventive concept.

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1.

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1.

FIG. 4 is a perspective view illustrating a microcavity according to theexemplary embodiment of FIGS. 1 to 3.

FIGS. 5 to 14 are cross-sectional views illustrating a method ofmanufacturing a liquid crystal display according to an exemplaryembodiment of the inventive concept.

DETAILED DESCRIPTION

Hereinafter, embodiments of the inventive concept will be described indetail with reference to the accompanying drawings. As those skilled inthe art would realize, the described embodiments may be modified invarious different ways without departing from the spirit or scope of theinventive concept.

In the drawings, the thickness of layers, films, panels, regions, etc.,may have been exaggerated for clarity. It will be understood that when alayer is referred to as being “on” another layer or substrate, it can beformed directly on the other layer or substrate, or formed on the otherlayer or substrate with one or more intervening layers therebetween.Like reference numerals designate like elements throughout thespecification.

FIG. 1 is a plan view illustrating a liquid crystal display according toan exemplary embodiment of the inventive concept. FIG. 2 is across-sectional view taken along line II-II of FIG. 1. FIG. 3 is across-sectional view taken along line III-III of FIG. 1. FIG. 4 is aperspective view illustrating a microcavity according to the exemplaryembodiment of FIGS. 1 to 3.

Referring to FIGS. 1 to 3, the liquid crystal display includes thin filmtransistors Qa, Qb, and Qc formed on a substrate 110. The substrate 110may be formed of transparent glass or plastic.

As shown in FIGS. 2 and 3, an organic layer 230 is formed on portions ofthe substrate 110 (where the thin film transistors Qa, Qb, and Qc areformed). A light blocking member 220 (e.g., horizontal light blockingmember 220 a or vertical light blocking member 220 b) is formed on thesubstrate 110 between adjacent organic layers 230. A pixel electrode 191is formed on portions of the organic layer 230 and the light blockingmember 220. Referring to FIG. 1, the pixel electrode 191 is electricallyconnected to a terminal of each of the thin film transistors Qa and Qbvia respective contact holes 185 a and 185 b. In some embodiments, theorganic layer 230 may be formed being elongated in a column direction ofthe pixel electrode 191.

In some embodiments, the organic layer 230 may serve as a color filter.A color filter may display one or more of the three primary colors (red,green, and blue). The color filter is not limited to the three primarycolors, and may also display one of cyan, magenta, yellow, andwhite-based colors.

Referring to FIG. 1, adjacent organic layers 230 may be spaced apartfrom each other in a horizontal direction D and in a vertical directionthat is perpendicular to the horizontal direction D. FIG. 2 depicts asection of the liquid crystal display in which adjacent organic layers230 are spaced apart from each other in the horizontal direction D. FIG.3 depicts a section of the liquid crystal display in which adjacentorganic layers 230 are spaced apart from each other in the verticaldirection.

Referring to FIG. 2, a vertical light blocking member 220 b is formed onthe substrate 110 between the adjacent organic layers 230 (which arespaced apart from each other in the horizontal direction D). As shown inFIG. 2, the vertical light blocking member 220 b is formed overlappingthe edges of the adjacent organic layers 230. In some embodiments, anoverlapping width between the vertical light blocking member 220 b andthe adjacent organic layers 230 may be substantially the same onopposite edges of the adjacent organic layers 230.

Referring to FIG. 3, a horizontal light blocking member 220 a is formedon the substrate 110 between the adjacent organic layers 230 (which arespaced apart from each other in the vertical direction). As shown inFIG. 3, the horizontal light blocking member 220 a is formed overlappingthe edges of the adjacent organic layers 230. In some embodiments, anoverlapping width between the horizontal light blocking member 220 a andthe adjacent organic layers 230 may be substantially the same onopposite edges of the adjacent organic layers 230.

As shown in FIGS. 2 and 3, a lower alignment layer 11 is formed on thepixel electrode 191. The lower alignment layer 11 may serve as avertical alignment layer. The lower alignment layer 11 may be formed ofmaterials which are generally used as a liquid crystal alignment layer,such as polyamic acid, polysiloxane, or polyimide.

As shown in FIGS. 2 and 3, a microcavity 400 is formed bounded by thelower alignment layer 11 and an upper alignment layer 21. Themicrocavity 400 may be formed in a column direction (i.e., verticaldirection) of the pixel electrode 191.

Referring to FIG. 3, the microcavity 400 has a liquid crystal injectionhole A formed at an edge of the microcavity 400. A liquid crystalmaterial including liquid crystal molecules 310 can be injected into themicrocavity 400 through the liquid crystal injection hole 400. In someembodiments, the liquid crystal material including the liquid crystalmolecules 310 may flow through the liquid crystal injection hole 400into the microcavity 400 via capillary action (capillary force).

In some embodiments, a hydrophobic layer is formed between adjacentmicrocavities 400. For example, as shown in FIG. 3, a first hydrophobiclayer 275 a is formed on a portion of the horizontal light blockingmember 220 a between the adjacent microcavities 400. The firsthydrophobic layer 275 a may contain elements such as carbon, hydrogen,or fluorine. The first hydrophobic layer 275 a may prevent liquidcrystal material from dispersing when the liquid crystal material isfirst dispensed (or injected) near the liquid crystal injection hole A.Specifically, a hydrophobic property of the first hydrophobic layer 275a allows the liquid crystal molecules 310 in the liquid crystal materialto maintain their original shapes when the liquid crystal material isflowing on the first hydrophobic layer 275 a.

As shown in FIGS. 2 and 3, a common electrode 270 is formed on the upperalignment layer 21, and an overcoat 250 is formed on the commonelectrode 270. A common voltage may be applied to the common electrode270, while a data voltage may be applied to the pixel electrode 191.Together, the common electrode 270 and the pixel electrode 191 maygenerate an electric field that determines the orientation of the liquidcrystal molecules 310 (located in the microcavity 400 between the twoelectrodes 270 and 191). Also, the common electrode 270 and the pixelelectrode 191 collectively constitute a capacitor that can maintain anapplied voltage even after the thin film transistor (e.g., Qa, Qb, orQc) has been turned off. The overcoat 250 may be formed of siliconnitride (SiNx) or silicon oxide (SiO2).

As shown in FIGS. 2 and 3, a supporting member 260 is formed on theovercoat 250. The supporting member 260 may include silicon oxycarbide(SiOC), a photoresist, or other organic materials. In some embodiments,a supporting member 260 including photoresist may be formed using acoating method. In some preferred embodiments, a supporting member 260including silicon oxycarbide (SiOC) may be formed using a chemical vapordeposition (CVD) method. The CVD method can produce silicon oxycarbide(SiOC) layers having high transmittance, low layer stress, and low layerdeformation.

Referring to FIG. 3, a groove GRV may be formed between the adjacentmicrocavities 400. In some embodiments, the groove GRV may be formedpassing through a microcavity 400, the upper alignment layer 21, thecommon electrode 270, the overcoat 250, and the supporting member 260.

Next, the microcavity 400 will be described in detail with reference toFIGS. 2 to 4.

Referring to FIGS. 2 to 4, the microcavity 400 is divided by a pluralityof grooves GRV (positioned at a portion overlapping with a gate line 121a) into a plurality of regions extending in the direction D of the gateline 121 a. The plurality of regions of the microcavity 400 maycorrespond to a plurality of pixel areas on the liquid crystal display.

A plurality of regions of the microcavity 400 formed in the verticaldirection is referred to as a group. When a plurality of groups isformed in a row direction, the grooves GRV dividing the microcavity 400may be positioned extending in the direction D of the gate line 121 a.As shown in FIG. 3, the liquid crystal injection hole A of themicrocavity 400 may be formed in a region corresponding to a boundarybetween the groove GRV and the microcavity 400.

The liquid crystal injection hole A is formed extending in the directionof the groove GRV. Referring to FIG. 2, an opening OPN may be formedbetween the adjacent microcavities 400 extending in the direction D ofthe gate line 121 a, with the opening OPN covered by the supportingmember 260.

As shown in FIG. 3, the liquid crystal injection hole A may be formed atan edge of the microcavity 400 between the upper alignment layer 21 andthe horizontal light blocking member 220 a (or between the upperalignment layer 21 and the lower alignment layer 11).

In some embodiments, the groove GRV may be formed extending in thedirection D of the gate line 121 a. In some other embodiments, thegroove GRV may be formed extending in a direction of the data line 171,and a plurality of groups (plurality of regions of the microcavity 400formed in the vertical direction) may be formed in a column direction.The liquid crystal injection hole A may be formed extending in thedirection of the groove GRV (being formed extending in the direction ofthe data line 171).

Referring to FIGS. 2 and 3, a passivation layer 240 is formed on thesupporting member 260. The passivation layer 240 may be formed ofsilicon nitride (SiNx) or silicon oxide (SiO2). As shown in FIG. 3, asecond hydrophobic layer 275 b is formed on the passivation layer 240.The second hydrophobic layer 275 b may include a first portion 275 b 1located above a top surface of the supporting member 260 and a secondportion 275 b 2 extending from the first portion 275 b 1, with thesecond portion 275 b 2 formed along a side surface of the supportingmember 260 that is adjacent to the groove GRV. The second hydrophobiclayer 275 b may include elements such as carbon, hydrogen, or fluorine.

The second hydrophobic layer 275 b can prevent mis-alignment of liquidcrystal material in the liquid crystal display. First, the mis-alignmentof liquid crystal material will be briefly described.

To allow the liquid crystal material to flow into the microcavity 400through the liquid crystal injection hole A (e.g., via capillaryaction), the liquid crystal material is first dispensed (injected) ontothe groove GRV. However, if the liquid crystal material is not dispensedaccurately at a predetermined position, mis-alignment of the liquidcrystal material may occur, resulting in dispersion of the liquidcrystal material to surrounding areas. As a result, the liquid crystalmaterial may not flow properly into the microcavity 400. For example,mis-alignment of the liquid crystal material may occur if the liquidcrystal material is inaccurately dispensed above a portion of thesupporting member 260 located near the groove GRV, or on top of thepassivation layer 240.

As mentioned above, the second hydrophobic layer 275 b can preventmis-alignment of the liquid crystal material. Specifically, the secondhydrophobic layer 275 b can prevent the liquid crystal material fromdispersing to another location, and can aid the flow of the liquidcrystal material towards the liquid crystal injection hole A (andmicrocavity 400). Similar to the first hydrophobic layer 275 a, ahydrophobic property of the second hydrophobic layer 275 b allows theliquid crystal molecules 310 in the liquid crystal material to maintaintheir original shapes when the liquid crystal material is flowing on thesecond hydrophobic layer 275 b.

It is noted that the second hydrophobic layer 275 b need not be formedabove the entire top portion of the supporting member 260. In someembodiments, the second hydrophobic layer 275 b may be formed above atop corner portion of the supporting member 260 which (the top cornerportion) is adjacent to the groove GRV where the liquid crystalinjection hole A is formed.

As shown in FIG. 3, a capping layer 280 is formed on the secondhydrophobic layer 275 b. The capping layer 280 may be formed coveringthe first portion 275 b 1 and the second portion 275 b 2 of the secondhydrophobic layer 275 b, with the liquid crystal injection hole A (ofthe microcavity 400) being exposed through the groove GRV. The cappinglayer 280 may be formed of a thermosetting resin, silicon oxycarbide(SiOC), or graphene.

In some embodiments, the capping layer 280 is formed of graphene. Thegraphene layer may serve as a capping layer to cap the liquid crystalinjection hole A. Graphene is suitable for use as a capping layerbecause it is highly impermeable to gases (such as helium). Although theliquid crystal material may contact the graphene layer, the liquidcrystal material will not be contaminated because graphene comprisescarbon bonds. In addition, the graphene capping layer can protect theliquid crystal material in the microcavity 400 from external oxygen andmoisture.

In some embodiments, the liquid crystal display may be formed withouthaving a separate upper substrate (since liquid crystal material isinjected through the liquid crystal injection hole A into themicrocavity 400).

In some embodiments, an overcoat (not illustrated) may be formed on thecapping layer 280. In some embodiments, the overcoat may be formed of aninorganic layer. In other embodiments, the overcoat may be formed of anorganic layer. The overcoat can help to protect the liquid crystalmolecules 310 (that are injected into the microcavity 400) from externalimpact. The overcoat also provides a planar layer on top of the cappinglayer 280.

Next, a liquid crystal display according to an exemplary embodiment willbe described with reference to FIGS. 1 to 3.

Referring to FIGS. 1 to 3, a plurality of gate conductors including aplurality of gate lines 121 a, a plurality of set-down gate lines 121 b,and a plurality of storage electrode lines 131 are formed on thesubstrate 110 (not illustrated).

The gate lines 121 a and the set-down gate lines 121 b extend primarilyin the horizontal direction D to transfer gate signals to the thin filmtransistors Qa, Qb, or Qc. A gate line 121 a includes a first gateelectrode 124 a protruding upward and a second gate electrode 124 bprotruding downward, and a set-down gate line 121 b includes a thirdgate electrode 124 c protruding upward. The first gate electrode 124 aand the second gate electrode 124 b are connected to each other to forma protrusion.

The storage electrode line 131 extends primarily in the horizontaldirection D to transfer a predetermined voltage (such as a commonvoltage Vcom). The storage electrode line 131 includes storageelectrodes 129 protruding both upward and downward, a pair of verticalportions 134 extending downward (substantially perpendicular to the gatelines 121 a), and a horizontal portion 127 connecting the pair ofvertical portions 134. The horizontal portion 127 includes a capacitorelectrode 137 extending downward.

In some embodiments, a gate insulating layer (not illustrated) may beformed on the gate lines 121 a, set-down gate lines 121 b, and storageelectrode lines 131.

In some embodiments, a plurality of semiconductor strips (notillustrated) may be formed on the gate insulating layer. Thesemiconductor strips may be formed of amorphous or crystalline silicon.The semiconductor strips may extend primarily in a vertical direction,and may include first and second semiconductors 154 a and 154 bextending toward the first and second gate electrodes 124 a and 124 b,respectively, with the first and second semiconductors 154 a/154 bconnected to each other, and a third semiconductor 154 c formed on thethird gate electrode 124 c.

In some embodiments, a pair of ohmic contacts (not illustrated) may beformed on each of the semiconductors 154 a, 154 b, and 154 c. An ohmiccontact may be formed of a material such as n+ hydrogenated amorphoussilicon having a high dopant concentration of silicide (or anothern-type impurity).

Next, a data conductor including a plurality of data lines 171, aplurality of first drain electrodes 175 a, a plurality of second drainelectrodes 175 b, and a plurality of third drain electrodes 175 c may beformed on the pairs of ohmic contacts.

A data line 171 transfers a data signal and extends primarily in avertical direction to cross a gate line 121 a and a set-down gate line121 b. Each data line 171 includes a first source electrode 173 a and asecond source electrode 173 b extending toward the first gate electrode124 a and the second gate electrode 124 b, respectively, with the firstsource electrode 173 a and the second source electrode 173 b connectedto each other.

Each of a first drain electrode 175 a, second drain electrode 175 b, andthird drain electrode 175 c includes a wide end and a rod-shaped end.The rod-shaped ends of the first drain electrode 175 a and the seconddrain electrode 175 b are partially surrounded by the first sourceelectrode 173 a and the second source electrode 173 b, respectively. Awide end of the first drain electrode 175 a extends to form a thirdsource electrode 173 c which is curved in the shape of a letter ‘U’. Awide end 177 c of the third drain electrode 175 c is formed overlappingwith the capacitor electrode 137 so as to form a set-down capacitorCstd. A rod-shaped end of the third drain electrode 175 c is partiallysurrounded by the third source electrode 173 c.

The first gate electrode 124 a, the first source electrode 173 a, andthe first drain electrode 175 a, together with the first semiconductor154 a, form a first thin film transistor Qa. The second gate electrode124 b, the second source electrode 173 b, and the second drain electrode175 b, together with the second semiconductor 154 b, form a second thinfilm transistor Qb. The third gate electrode 124 c, the third sourceelectrode 173 c, and the third drain electrode 175 c, together with thethird semiconductor 154 c, form a third thin film transistor Qc.

The semiconductor strips including the first semiconductor 154 a, thesecond semiconductor 154 b, and the third semiconductor 154 c may havesubstantially the same planar shape as the conductors 171, 173 a, 173 b,173 c, 175 a, 175 b, and 175 c and the ohmic contacts, with theexception of the channel regions formed between the source electrodes173 a, 173 b, and 173 c and the drain electrodes 175 a, 175 b, and 175c.

The first semiconductor 154 a includes an exposed portion between thefirst source electrode 173 a and the first drain electrode 175 a whichis not covered by the first source electrode 173 a and the first drainelectrode 175 a. The second semiconductor 154 b includes an exposedportion between the second source electrode 173 b and the second drainelectrode 175 b which is not covered by the second source electrode 173b and the second drain electrode 175 b. The third semiconductor 154 cincludes an exposed portion between the third source electrode 173 c andthe third drain electrode 175 c which is not covered by the third sourceelectrode 173 c and the third drain electrode 175 c.

A lower passivation layer (not illustrated) may be formed on theconductors 171, 173 a, 173 b, 173 c, 175 a, 175 b, and 175 c and theexposed portions of the semiconductors 154 a, 154 b, and 154 c. Thelower passivation layer may be formed of an inorganic insulator such assilicon nitride or silicon oxide.

A color filter (e.g., organic layer 230) may be formed on the lowerpassivation layer. The color filter may be formed on most regions of thelower passivation layer, except the portions of the lower passivationlayer where the first thin film transistor Qa, second thin filmtransistor Qb, and third thin film transistor Qc are formed. The colorfilter may be formed being elongated in a vertical direction along aspace between adjacent data lines 171. In some embodiments, the colorfilter may be formed below the pixel electrode 191 and the commonelectrode 270.

A light blocking member 220 may be formed on the substrate 110 betweenadjacent color filters (e.g., organic layers 230) and on edge portionsof the color filter. The light blocking member 220 may extend upwardalong the gate line 121 a and downward along the set-down gate line 121b. The light blocking member 220 may include a first light blockingmember 220 a covering the regions where the first thin film transistorQa, second thin film transistor Qb, and third thin film transistor Qcare formed, and a second light blocking member 220 b extending along thedata line 171.

The light blocking member 220 is sometimes referred to as a black matrixand may be capable of reducing light leakage.

A plurality of contact holes 185 a and 185 b exposing the first drainelectrode 175 a and the second drain electrode 175 b, respectively, maybe formed in the lower passivation layer and the light blocking member220.

A pixel electrode 191 (including a first subpixel electrode 191 a and asecond subpixel electrode 191 b) is formed on portions of the colorfilter and the light blocking member 220. The first subpixel electrode191 a and the second subpixel electrode 191 b are separated from eachother, with the gate line 121 a and set-down gate line 121 btherebetween disposed at the upper and lower portions and adjacent toeach other in a column direction. A height of the second subpixelelectrode 191 b may be greater than a height of the first subpixelelectrode 191 a. In some embodiments, the height of the second subpixelelectrode 191 b may be about 1 to 3 times greater than the height of thefirst subpixel electrode 191 a.

The shape of each of the first subpixel electrode 191 a and the secondsubpixel electrode 191 b is a quadrangle. Each of the first subpixelelectrode 191 a and the second subpixel electrode 191 b includes a crossstem. The cross stem includes horizontal stems 193 a and 193 b, andvertical stems 192 a and 192 b crossing the horizontal stems 193 a and193 b. The first subpixel electrode 191 a includes a plurality of minutebranches 194 a and a lower protrusion 197 a. The second subpixelelectrode 191 b includes a plurality of minute branches 194 b and anupper protrusion 197 b.

The pixel electrode 191 is divided into four subregions by thehorizontal stems 193 a and 193 b and the vertical stems 192 a and 192 b.The minute branches 194 a and 194 b extend obliquely from the horizontalstems 193 a and 193 b and the vertical stems 192 a and 192 b. Theextending directions of the minute branches 194 a and 194 b may form anangle of about 45 degrees or 135 degrees with the gate lines 121 a and121 b or with the horizontal stems 193 a and 193 b. The extendingdirections of the minute branches 194 a and 194 b of two adjacentsubregions may also be perpendicular to each other.

In some embodiments, the first subpixel electrode 191 a further includesan outer stem surrounding an outer portion The second subpixel electrode191 b further includes horizontal portions positioned at the top and thebottom portions of the first subpixel electrode 191 a, and left andright vertical portions 198 positioned at the left and the rightportions of the first subpixel electrode 191 a. The left and rightvertical portions 198 may prevent capacitive coupling that may occurbetween the data line 171 and the first subpixel electrode 191 a.

The lower alignment layer 11, the microcavity 400, the upper alignmentlayer 21, the common electrode 270, the overcoat 250, and the cappinglayer 280 are formed on or above the pixel electrode 191. Theaforementioned elements are the same as those described above in FIGS. 2and 3, and further description of these elements shall be omitted.

The liquid crystal display embodiment described above is an example of avisibility structure that allows side visibility to be improved. Thestructure of the thin film transistor and the design of the pixelelectrode are not limited to the structure described in the aboveembodiment, and may be modified accordingly within the spirit and scopeof the inventive concept.

Next, an exemplary method of manufacturing the above liquid crystaldisplay embodiment will be described with reference to FIGS. 5 to 14.FIGS. 5, 7, 9, and 13 illustrate cross-sectional views taken along lineII-II of FIG. 1 at different stages of fabrication of the liquid crystaldisplay, and FIGS. 6, 8, 10, 11, 12, and 14 illustrate cross-sectionalviews taken along line III-III of FIG. 1 at different stages offabrication of the liquid crystal display.

Referring to FIGS. 5 and 6, thin film transistors Qa, Qb, and Qc (see,e.g., FIG. 1) are formed on a substrate 110. The substrate 110 may beformed of transparent glass or plastic. An organic layer 230 is formedon portions of the substrate 110 (where the thin film transistors Qa,Qb, and Qc are formed), with each portion corresponding to a pixel area.A light blocking member 220 (e.g., horizontal light blocking member 220a and vertical light blocking member 220 b) is formed on the substrate110 between adjacent organic layers 230.

Next, a pixel electrode 191 (having minute branches) is formed onportions of the organic layer 230 and the light blocking member 220. Thepixel electrode 191 may be formed of a transparent conductor such as ITOor IZO.

Next, a sacrificial layer 300 is formed on the pixel electrode 191. Insome embodiments, the sacrificial layer 300 may be formed of siliconoxycarbide (SiOC), a photoresist, or an organic material. In someembodiments, a sacrificial layer 300 including silicon oxycarbide (SiOC)may be formed using a chemical vapor deposition method. In some otherembodiments, a sacrificial layer 300 including a photoresist may beformed using a coating method. The sacrificial layer 300 is patterned toform a groove GRV in a direction substantially parallel to a signal linethat is connected to a terminal of a thin film transistor. Thesacrificial layer 300 is also patterned to form an opening OPN in asubstantially vertical direction that is perpendicular to the grooveGRV.

Referring to FIGS. 7 and 8, the common electrode 270, the overcoat 250,and the supporting member 260 are sequentially formed on the sacrificiallayer 300.

The common electrode 270 may be formed of a transparent conductor suchas ITO or IZO. The overcoat 250 may be formed of silicon nitride (SiNx)or silicon oxide (SiO2). In some embodiments, the supporting member 260may be formed of a material that is different from the sacrificial layer300.

The common electrode 270, overcoat 250, and supporting member 260 may beformed on or above the sacrificial layer 300 to completely fill theopening OPN. Next, as shown in FIG. 8, portions of the common electrode270, overcoat 250, and supporting member 260 above the horizontal lightblocking member 220 a may be removed to form a groove GRV. The grooveGRV provides a passage for removing the sacrificial layer 300 to form amicrocavity 400 (shown in FIG. 9).

Referring to FIGS. 9 and 10, the sacrificial layer 300 in FIGS. 7 and 8is removed. The sacrificial layer 300 may be removed using O₂ ashing ora wet-etching method. The removal of the sacrificial layer 300 resultsin a microcavity 400 having a liquid crystal injection hole A formed atan edge of the microcavity 400. The microcavity 400 is an empty spacethat is formed as a result of removing the sacrificial layer 300. Theliquid crystal injection hole A may be formed in a direction parallel toa signal line that is connected to a terminal of the thin filmtransistor.

Referring to FIG. 11, plasma processing (“PP”) is performed on themicrocavity 400. The surface of the pixel electrode 191 and the surfaceof the common electrode 270 within the microcavity 400 may have ahydrophilic property after the plasma processing PP. The plasmaprocessing PP includes oxygen plasma, which may be obtained from gasessuch as O₂, O₃, NO, N₂O, CO, or CO₂. A processing pressure during theplasma processing PP may range from about 10⁻³ torr to 10 torr, and aprocessing temperature may range from about −20° C. to 80° C. Further,an inflow amount of injected gas may range from about 10 sccm (standardcubic centimeter per minute) to 10,000 sccm.

During subsequent processing, when an alignment material is injectedinto the groove GRV, the alignment material may enter the microcavity400 through the liquid crystal injection hole A via capillary action(capillary force). As previously mentioned, after the alignment materialis dispensed (or injected), the alignment material typically requires adrying step to drive out the solvents in the alignment material.However, after drying of the alignment material, the solids in thealignment material may coalesce to form large clusters of solids. Thelarge clusters of solids can obstruct the flow of the liquid crystalmaterial into the liquid crystal injection hole A and the microcavity400. However, if an inner wall of the microcavity 400 has a hydrophilicproperty, the solids in the alignment material can be dispersed withoutcoalescing together after the drying of the alignment material.

By performing the plasma processing PP, the inner wall of themicrocavity 400 may have a hydrophilic property, and the surfaces of thesupporting member 260 or the passivation layer 240 may also have ahydrophilic property. As mentioned above, the hydrophilic property ofthese surfaces allows solids to be dispersed and prevents the solidsfrom coalescing together after the drying of the alignment material.Accordingly, the risk of solids obstructing the flow of liquid crystalmaterial into the liquid crystal injection hole A and microcavity 400can be reduced in the above embodiments.

Referring to FIG. 12, a first hydrophobic layer 275 a is formed on aportion of the horizontal light blocking member 220 a between theadjacent microcavities 400. A second hydrophobic layer 275 b is formedon the passivation layer 240 and a side portion of the supporting member260. The second hydrophobic layer 275 b may include a first portion 275b 1 formed above a top surface of the supporting member 260, and asecond portion 275 b 2 extending from the first portion 275 b 1, withthe second portion 275 b 2 formed on a side surface of the supportingmember 260 along the side of the groove GRV.

The first hydrophobic layer 275 a and the second hydrophobic layer 275 bmay include elements such as carbon, hydrogen, or fluorine, and may beformed using a chemical vapor deposition method or a sputtering method.When the first hydrophobic layer 275 a and the second hydrophobic layer275 b are formed using a sputtering method, a processing pressure mayrange from about 10⁻² torr to 10 torr, a processing temperature mayrange from about 20° C. to 300° C., and an inflow amount of injected gasmay range from about 10 sccm (standard cubic centimeter per minute) to10,000 sccm.

The first hydrophobic layer 275 a and the second hydrophobic layer 275 bcan prevent liquid crystal material from dispersing when the liquidcrystal material is first dispensed (or injected) onto the groove GRV. Ahydrophobic property of the first hydrophobic layer 275 a and the secondhydrophobic layer 275 b also allows the liquid crystal molecules 310 inthe liquid crystal material to maintain their original shapes when theliquid crystal material is flowing on the first hydrophobic layer 275 aand/or the second hydrophobic layer 275 b.

Referring to FIGS. 13 and 14, alignment layers 11 and 21 arerespectively formed on the pixel electrode 191 and the common electrode270 by dispensing (injecting) an alignment material onto the groove GRV,into the liquid crystal injection hole A and microcavity 400. After thealignment material is injected, the alignment material flows through theliquid crystal injection hole A into the microcavity 400 via capillaryaction (capillary force). In some embodiments, the alignment layers 11and 21 are formed after the hydrophobic layers 275 a and 275 b have beenformed. In yet other embodiments, the hydrophobic layers 275 a and 275 bare formed after plasma processing PP, and after the alignment layers 11and 21 have been formed.

As previously mentioned, the dispensed liquid crystal material(including the liquid crystal molecules 310) can flow into themicrocavity 400 via capillary action (capillary force) through thegroove GRV and the liquid crystal injection hole A. Since the firsthydrophobic layer 275 a is formed in a region adjacent to the liquidcrystal injection hole A, the liquid crystal material is not dispersedwhen the liquid crystal material is dispensed (or injected) onto thegroove GRV. Also, as previously mentioned, a hydrophobic property of thefirst hydrophobic layer 275 a allows the liquid crystal molecules 310 inthe liquid crystal material to maintain their original shapes when theliquid crystal material is flowing on the first hydrophobic layer 275 a.The second hydrophobic layer 275 b is formed above a top surface of thesupporting member 260 and located near the groove GRV. Accordingly, evenif mis-alignment occurs during the dispense of the liquid crystalmaterial, the second hydrophobic layer 275 b may still guide the liquidcrystal material toward the liquid crystal injection hole A, whilemaintaining the original shape of the liquid crystal molecules 310 asthe liquid crystal material is flowing on the second hydrophobic layer275 b.

Next, a capping layer 280 is formed to cover the liquid crystalinjection hole A according to the embodiments described in FIGS. 2 and3. The capping layer 280 covers the top and the side walls of thesupporting member 260, and also covers the liquid crystal injection holeA being exposed by the groove GRV. The first hydrophobic layer 275 a andthe capping layer 280 may be formed in contact with each other in thegroove GRV. As previously mentioned, the capping layer 280 may be formedof a thermosetting resin, silicon oxycarbide (SiOC), or graphene.

While the inventive concept has been described with reference to someembodiments, it is to be understood that the inventive concept is notlimited to the disclosed embodiments, and is intended to cover variousmodifications and equivalent arrangements within the spirit and scope ofthe inventive concept.

What is claimed is:
 1. A liquid crystal display, comprising: asubstrate; a thin film transistor disposed on the substrate; a pixelelectrode connected with a terminal of the thin film transistor; asupporting member facing the pixel electrode; a liquid crystal layerdisposed in a plurality of microcavities between the pixel electrode andthe supporting member; an upper hydrophobic layer disposed on an edgeportion of the supporting member and on the supporting member which isdisposed on the liquid crystal layer; a lower hydrophobic layer disposedbetween adjacent microcavities and in a region corresponding to agroove; and a capping layer disposed on the supporting member wherein anoverlapping area of the lower hydrophobic layer and the pixel electrodeis smaller than both a surface area of the lower hydrophobic layerfacing the substrate and a surface area of the pixel electrode facingthe substrate.
 2. The liquid crystal display of claim 1, wherein: thecapping layer covers the groove.
 3. The liquid crystal display of claim2, wherein: the lower hydrophobic layer and the capping layer aredisposed in contact with each other in the groove.
 4. The liquid crystaldisplay of claim 3, wherein: the upper hydrophobic layer includes afirst portion disposed at a top surface of the supporting member and asecond portion extending from the first portion, with the second portiondisposed on a surface of the supporting member along a lateral surfaceof the groove.
 5. The liquid crystal display of claim 4, furthercomprising: an organic layer disposed on portions of the substrate; anda light blocking member disposed between adjacent organic layers,wherein the lower hydrophobic layer is disposed on a portion of thelight blocking member.
 6. The liquid crystal display of claim 1, furthercomprising: a common electrode disposed between the liquid crystal layerand the supporting member.
 7. The liquid crystal display of claim 6,wherein: a surface of the pixel electrode facing the liquid crystallayer and a surface of the common electrode facing the liquid crystallayer have a hydrophilic property as a result of being subjected tohydrophilic processing.
 8. The liquid crystal display of claim 7,further comprising: an alignment layer disposed between the pixelelectrode and the liquid crystal layer, or between the common electrodeand the liquid crystal layer.
 9. The liquid crystal display of claim 1,wherein: the upper hydrophobic layer includes carbon, hydrogen, orfluorine.